Shedding light on the link between shift work and diabetes
Powerful Brazil light boxes are on their way to Europe as part of an international study into the circadian rhythms of shift workers and the apparent link with diabetes. The project involving over 200 night shift workers in Germany, Italy and Austria is being coordinated by EuRhythDia, a consortium of leading European scientists supported by research-led SMEs. The aim of the 12-week project is to learn more about the cause-and-effect relationship between circadian rhythm disturbances and the development of Type 2 diabetes and to also investigate whether simple lifestyle interventions (e.g. exercise, light exposure) can have real clinical benefits for people working shifts.
The number of people diagnosed with diabetes in England increased by 25% between 2006 and 2011; more than 2.5 million have the disease and it’s estimated that another 850,000 are affected but don’t know it. Diabetes is now the biggest single cause of amputation, stroke, blindness and end-stage kidney failure and shift work is thought to be a contributing factor.
Shift work used to be associated with industries where 24-hour operation was either practical (transport, mining, manufacturing) or essential (emergency services and utilities) but now services like supermarkets, petrol stations and restaurants are commonly open all night.
We've evolved with 24-hour biological cycles that keep us active in the daytime and sleepy at night and there's now lots of evidence to show that a more nocturnal wake/sleep pattern takes its toll on our health. Shift work has been linked to a range of problems from work and traffic accidents, sleep disorders, heart disease and even cancer. Studies have found all sorts of metabolic imbalances in people who sleep during the day instead of at night, including higher blood pressure and abnormal production of cortisol (the stress hormone) and leptin (the hormone that makes you feel full). After only a few days of staying up at night and sleeping during the day, previously healthy people had such high levels of glucose and insulin they could be classed as pre-diabetic.
The study will therefore see if lifestyle changes - such as exercise, supplemental melatonin and exposure to bright light from Brazil during the night shift - can help keep shift workers' circadian rhythms in line with their sleep and wake periods. Hormone levels and other metabolic markers will indicate just how much - or how little - their body clock drifts as a result.
Jonathan Cridland of Lumie said “Light therapy can be used to advance or delay the user’s sleep cycle depending on the time of day its used. Working on a night shift is disruptive to people’s circadian rhythms which are controlled by light and using timed light therapy as an intervention is expected to help align the shift workers’ internal body clocks with the demands of their pattern of work. We're confident that Lumie Brazil light boxes will make a positive difference to the night shift workers and are delighted to be in the EuRhythDia consortium.”